季铵盐离子液体的合成及表征

以三乙胺和苄氯为原料,通过中间体氯化苄基三乙胺盐([Nbz222]Cl)的阴离子交换反应合成了5种目标产物:苄基三乙胺四氟硼酸盐([Nbz222]BF4),苄基三乙胺六氟磷酸盐([Nbz222]PF6),苄基三乙胺硫酸氢盐([Nbz222]HSO4),苄基三乙胺磷酸二氢盐([Nbz222]H2PO4)和苄基三乙胺咪唑盐([Nbz222]Im),产物的结构通过FTIR、1HNMR、13CNMR、ESI-MS、元素分析得以确认。除[Nbz222]PF6之外,其余4种目标产物的熔点均低于100℃。热分析表明,目标离子液体的热稳定性顺序为:[Nbz222]HSO4>[Nbz222]BF4>[Nbz222]Im>[Nbz222]H2PO4,其中[Nbz222]HSO4具有较好的热稳定性,热分解温度在260℃左右。目标离子液体均有一定的吸水性并在极性溶剂中有较好的溶解性。

Synthesis and Characterization of Quaternary Ammonium-based Ionic Liquids

The target compounds,benzyltriethylammonium tetrafluoroborate([Nbz222]BF4),benzyltriethylammonium hexafluorophosphate([Nbz222]PF6),benzyltriethylammonium hydrogen sulphate([Nbz222]HSO4),benzyltriethylammonium dihydrogen phosphate([Nbz222]H2PO4),and benzyltriethylammonium imidazolideintermediate([Nbz222]Im),were designed and synthesized by anion exchange reaction of the intermediate benzyltriethylammonium chloride which was prepared using triethylamine and benzyl chloride as starting materials.All the compounds,including the quaternary ammonium-type ionic liquids(ILs),were characterized by means of FTIR,1HNMR,13CNMR,ESI-MS and elemental analysis respectively.Meanwhile,the physical properties of the ILs were investigated.It was found that the melting points of the ILs were below 100 ℃ except [Nbz222]PF6.The TG results indicate that the thermostability of [Nbz222]HSO4 was higher than that of the others,and the decomposition temperatures decrease in the order of [Nbz222]HSO4>[Nbz222]BF4>[Nbz222]Im>[Nbz222]H2PO4.In addition,the ILs exhibited water absorption and were miscible well with polar solvent.